The invention relates to improvements in machines for winding webs of material like paper onto web reels. More particularly, the invention relates to improvements in guards for the inlet sides of nips between various rolls, drums and reels in such machines. Still more particularly, the invention relates to machines where the size of the reel being wound and forming the nip increases over time.
This invention provides a winding machine comprising a support drum, a winding tube at least partially supported on the support drum, and a web of material being wound around the winding tube to form a web reel in response to rotation of the support drum and the web reel, the point where the web reel rotates into contact with the support drum being called the nip. The winding machine further includes a nip safety guard comprising a finger presence sensor, a support mechanism supporting the finger presence sensor adjacent one of the web reel and the support drum, and a moving mechanism that moves and locates the finger presence sensor support mechanism depending on the size of the web reel So that the finger presence sensor is located closely adjacent the one of the web reel and the support drum and spaced a safe distance from the nip. The safety guard moving mechanism further includes a control for determining the size of the web reel and operating the moving mechanism to position the finger sensor. More particularly, the winding machine nip safety guard comprises a safety shield that covers the support drum and is mounted for rotation about the support drum, the safety shield having an edge adjacent the nip, and the moving mechanism moves the safety shield away from the nip during higher speed winding and towards the nip when winding at significantly lower speeds. The safe distance is one so that if a finger is sensed, the winding of the web reel can be stopped in time to prevent the finger from reaching the nip. More particularly, the safety shield has an edge adjacent the nip, and the finger presence sensor is mounted on the safety shield edge.
In the preferred embodiment, the safety shield covers the support drum, and the safety guard moving mechanism is mounted for rotation about the axis of the support drum.
The principal feature of the invention is the provision of a safety guard that moves up to the nip when the web reel is being rethreaded and positions itself so that a finger sensor is adjacent the nip to stop the winding machine if a finger is sensed near the nip.